Pearly Cockle (also known as the Egg Cockle or Smooth-edged Cockle)
Phylum: Mollusca, Class: Bivalvia, Order: Cardiida, Family: Cardiidae, Genus: Chione, Species: Chione cancellata · Cardiidae (Cockle family) · Bivalve (two-shelled clam), whole shell, fan-shaped to rounded triangular
Species
Laevicardium mortoni (Morton's Egg Cockle) or similar Protothaca/Chione species
Shell Type
Bivalve (two-shelled clam), whole shell, fan-shaped to rounded triangular
Family
Cardiidae (Cockle family)
Size
Approximately 1 to 1.5 inches in length, which is average for this species. Adults typically range from 0.75 to 2 inches.
Color & Pattern
Dark greyish-brown base with pronounced darker radial ribs and lighter banding near the umbo. The interior is not visible, but exterior colors appear natural and slightly weathered.
Rarity
Very Common, frequently found washed up on beaches throughout its range.
Habitat
Shallow intertidal and subtidal zones, typically found buried just beneath the surface of sandy or muddy bottoms in bays and estuaries.
Geographic Range
Western Atlantic Ocean, extending from North Carolina through the Gulf of Mexico, Caribbean Sea, and down to Brazil.
Description
A sturdy, compact bivalve featuring prominent, strong radial ribs crossed by fine concentric lines, creating a distinct grid-like or cancellate texture. The shell is roughly triangular-oval in shape with a prominent, slightly pointed umbo.
Key Features
Heavy, prominent radial ribs and concentric ridges forming a lattice (cancellate) pattern, a solid, rounded-triangular outline, and strong interlocking teeth along the hinge line.
Collector Value
Low to moderate commercial value. While extremely popular among beginner beachcombers and shell crafters, they are too common to command high prices among serious advanced collectors, typically valued at under a dollar per specimen.
Condition Notes
Good condition. The exterior sculpture is mostly intact with minor natural wear on the umbo. No major fractures or predator bore holes are visible. Collectibility grade is Good.
Interesting Facts
Cockles are capable of using their muscular, hatchet-shaped foot not only for burrowing into the sand but also to leap or flip themselves away from danger or predators like starfish.
Ecological Role
Bivalves like this play a vital ecological role as filter feeders, helping to clean the water column. They serve as an important food source for shorebirds, fish, and carnivorous snails.
Similar Species
Crossed Ark (Anadara transversa) or other small Venus clams (Chione species), which can be distinguished by different hinge structures and finer or less symmetrical ribbing.
Beach Finding Tips
Look along sandy Gulf and Atlantic beaches at low tide, particularly near tidal inlets, passes, and wrack lines where wave action deposits small shells.